Internal-combustion engine.



T. LAFHTE. NTERNM. COMBUST APPUCATlON FILED N 10N ENG\NE.

Patented June 13, 1916.

AUivrrnn STATES `PATENT oFFioE.

grHoDoRE JLAEITTE, yor PARIS, FRANCE.

To all whom t may concern.'

Be itV known that I, Tiiooonn LAFITTE, citizen of the French Republic, residing at Paris, Department of the Srine, in France,

have .invented certain ne'w and useful Improvements in Internal-Combustion En-. gines); and I do hereby declare the following to be a full, cleai, and exact desci'iption of the invention, such as will enable otheis skilled in the artto whichV it appertains to.

make and use the same.

The present invention has for its object,

the provision of an explosion engine with one or more cylinders, its distribution, which is of the four-cycle type, being provided for by Imeans of a single slide vvalve or sleeve which is' preferably, but not necessarily, concentric with the driving piston.v Thisslide valve or sleeve which forms the distributer is connected by a connecting rod with an element to which a combined oscillatory and reciprocator-y motion isI imparted. Owing to this connection, the slide valve or sleeve efvfeats al reciprocating rectilinear movement or reciprocating rotary movement, so that it is able to produce the phases of the distribution.

The valve sleeve is provided with twol orifices serving alternately for the exhaust and admission. This arrangement enables the fresh gases to cool the apertures pref viously exposed to the burnt gases. Fur-` thermore, the extremity of the sleeve slides on a cylinder'end which isfitt'ed internallyl and forms a hermetic cover. This cylinder end, which may be held by means`V of a single central nut, permits of a single water outlet and facilitates the construction of a monobloc motor without water piping.

The form of the curve described by the lower extremity of the rod controlling the slide valve varies considerably when the relative values of the elements l.forming the mechanical connection are modified. If this curve presents the formof 'a figure 8 with two substantially equal loops, the movement of the valve caused by the rodin describing one of these loops, can be utilized for the admission and the other for the exhaust.

The arrangement may also be lsuch that one Specication of Letters Patent.

In the accompanying drawing: Figure 1 is a vertical cross section of the motor; Fig.

e Patented J unie 13,1916.

Application filed November 9, 1911. Serial No. 659,319. i i

2 represents anA 8-shaped curve with two equal loopswhich is described by the lower extremity ofthe rod; Fig. 3 is illustrative of the. case in which the curve described by the lower extremity of the rod presents the form of a figure 8, one of the loops of which `is relatively' small; Fig. 4 shows the curve comprising only a single loop; Fig. 5 shows another arrangement in which the curve represents a Pascal snail.

The sleeve 2 slides in the cylinder 1 and is provided near its extremity with the admission and exhaust orifices 3 and 4. These orifices are symmetrical and may open re-k spectively into two passages 5 and 6, formed in the guide cylinder 1, opposite two double 'caps 7 and 8 secured to 'either side of the motor. These double ca-ps are connected-,respectively by two collectors 9 and 10, of which 9 communicates with the carbureter and l0 with the exhaust.` In the saine cap, the conduits serving for' the admission and the exhaust are separated by a space 11 in communication with the atmosphere. The

admission gases are thus but slightly heated by contact with the burnt gases and enter suiiciently fresh to efiicaciously fulfil their purpose of cooling the orifices in the sleeve.

At its upper extremity, the sleeve 2y is guided by the cylinder end 12, which is fitted internally and fixed to the guide cylinder 1 by means of a central nut 13. At its lower part, the sleeve 2 is connected by the pitman 14 with the slide-block 15 at 'the point 16; the slot or guideway 17, which oscillates around trunnions 18, guides the slide-block 15, which is pivoted at 19, to the crank shaft 20. In these conditions, as the y straight line 19-16 always passes through the point 18,-andas the distance 19-16 remains constant, it is obvious that the curve described by the point 16. is the conchoid relatively to the point 18, and the circle C described by the point 19, the constant of this distance be designated by m and the distance 18-20 by a, the radius of the circlev 'C by 1', then the form of the' conchoid A ioo ` the oonchoid being the distance 19-16. If i -cumference described by 19, is divided into four parts which correspond to the angles adopted for the four-cycle distribution. These angles are indicated at: 21--22 exhaust angle. 22-23 angle between closing the exhaust and opening the admission. 23-24 admission angle. 24-21 compression, explosion and expansion angle. The stud 19 describes these angles in succession in the direction indicated by `the arrow and causes the pin 16 of the rod 14 to traverse the parts al1-221, aal-231, 231-241, 241- 211 corresponding to the 8-shaped curve. From 211 to 221, the pin 16 rises and bythe intermediary of the pitman 14, lifts the sleeve 2, causes itv to open the orifices 5, and then brings it downward and closes the exhaust. From 221 to 231, the pin 16 continues its travel, the openings 5 and 6 are closed, the sleeve descends rapidly from 231 to 241, it opens the admission orifices 6, and the pin 16 containing its travel, lifts the sleeve which closes the admission 6. From 241 to 211, the pin 16 at first slightly lifts the sleeve, then lowers it, then lifts it again and continuing, reaches at 211 the point of open-V ing the exhaust orifices, andthe cycle recom.

mences. If the length m be taken suficiently close to a-i-r, it is possible to obtain a curve A representing a loop of very vsmall size, (Fig. 3)'. The small loop may be made to correspond to an ineffective displacementl of the slide valve, by suitably arranging the orifice 4 of the slide valve 2 and the exhaust and admission orices' and 6. If this condition is fulfilled, the portion p g of the curve A will correspond to the exhaust andA the arc s t to the admission. While the point 16 describes the arc t p, the compression phase is produced in the cylinder and then the explosion and the expansion. If the constant m of the conchoid is equal to a-i-r, -the curve with a single loop represented in Fig. 4 is obtained; the arcs p g and s t corresponding respectively top'the exhaust and the admission. l

In the arrangement illustrated in Figs. 2, 3, and 4, the point 16 describes'the entire curve A during one revolution of the crank 20. It is for this reason that the shaft 20 is driven olf the driving shaft at half speed. When the shaft 18 is located at a distance from the shaft 20 equal to the radius' of the crank, a Pascal snail is obtained, the form of which depends upon the valeA of the constantl m. If, for example, lml is smaller than the diameter 2f, the arrangement may be such that the small loop corresponds to an idle travel of the distributing sleeve 2, the orifice. 4 not being uncovered. Thev arc p g (Fig. 5) of the large loop will correspond to the exhaust, the arc s t to the admission. Whlle the point 16 describes the arc t lv p, the compression.,v the explosion, and the expansion will take' place. To cause the point 16 to describevthe entire curve A, it is necessary that the crank 20 should effect two revolutions; In this manner, a four stroke cycle is obtained by keying the crank shaft 2O directly on the driving shaft. This arrangement presents the advantage of greatly simplifying the mechanism and of rendering the speed reducing gear usuall employed for driving the distribution sha unnecessary.

What I claim is:-

1. In an4 internal combustion engine provided with suitable ports in the cylinder walls, a'valve mounted in said cylinder to coperate with said ports, a pitman pivoted to said valve, a pivoted guide-way, a block slidably mounted insaid guide-way, said pitman being pivoted directly lto said block, and means to impart a rotary motion to one end of said sliding block.

. 2. In an internal combustion engine provided with suitable ports in the cylinder walls, a valve mounted in said cylinder to coperate with said ports, a pitman pivoted to said valve, a slide to which 4said pitman is directly pivoted, a pivoted guideway in which said slide is mounted to re ciprocate, and means to impart a rotary motion to one end of said slide to reciprocate the same in the guide and alsoto oscillate the guide.

3. In an internal combustion engine provided with suitable ports in the cylinder walls, a valve sleeve mounted in said cylinder to coperate with said ports, a pitman pivoted to said sleeve, a slide to whichsad .pitman is directly pivoted, a guide-way pivoted to a stationary part of the engine and in which said slide is adapted to reciprocate, a rotary member disposed adjacent vthe slide and to one side of the pivot point of said guide-way, the slide being pivoted directly to said rotary member whereby the slide is reciprocated in the guide-way and the guide-way'simultaneously oscillated, for the purpose described.

In testimony whereof I aflix my signature, in presence of two witnesses.

THODORE LAFITTE. Witnesses: Y

DEAN vB. MASON. EMILE KLoTz.

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